The Loch Lomond Readvance in the Uig Hills, western Lewis, Scotland

Geomorphological mapping of the Uig Hills provides evidence for four locally-nourished valley glaciers with a total area of 11.69 km(2). A Loch Lomond Stadial (-12.9-11.5 ka BP) age for this glacial episode is indicated by the radial configuration of reconstructed glaciers, the landform assemblage and the absence of frost-weathered rock inside its limits. Recessional moraines extend upvalley from former glacier termini, implying that glacier retreat was driven by gradual climatic forcing. The mean equilibrium line altitude ( ELA) of the glaciers is calculated as 212 m, consistent with a northwards ELA decrease along the western seaboard of Great Britain of 68.5 m/ 100 km, equivalent to a latitudinal summer temperature gradient of -0.41 degrees C/100 km. A mean July sea-level temperature of -7.1 degrees C is inferred for the coldest part of the stade. Average accumulation at the ELA is estimated to have been 2585 +/- 200 mm, much of which probably comprised snow blown from adjacent ground.